Automatic saw sharpening machine



Aug. 22, 1950 I r "E. J. DUQUETT E I AUTOMATIC SAW SHARPENING MACH INE 4 Sheets-Sheet 2 Filed Sept. 26,1949

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T 'ae AUTOMATIC SAW SHARPENING MACHINE Filed Sept. 26, 1949 I 4 Sheets-Sheet I5 f l I 144 26 I0 20 INVENTOR.

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Aug. 22, 1 950 E. J. DUQUETTE 2,519,743

I AUTOMATIC SAW SHARPENING MACHINE Filed Sept, 26, 1949 4 Sheets-Sheet 4 I Fl .7.

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Patented Aug. 2 2, 1950 uNlT-so STATES, PATENT OFFICE Edward J. Duquette, Sommersworth, N. H. Application September 26, 1949, Serial No. 117,879

- ,liliis invention relates to novel and useful improvements in saw Sharpeners.

- An object of this invention is to sharpen a saw or other work piece by a grinder which is carried by a pivotal assembly, the grinder being lifted fromone tooth to the other of the saw; the pivotal feature being employed for the purpose of obtaining adjustmentwith respect to the saw teeth, the saw being moved in stages or short distances after each tooth is ground.

Another object of this invention is toimprove the means of moving the saw supporting carriage in a horizontal plane the short distances, which improved means consists of a bracket which is mounted on a support for pivotal movement, the bracket being engaged by a reciprocating element which causes the bracket to be pivoted whereby the dog which is carried by the bracket causes movement of the carriage in response to each pivotal operation of the bracket.

A further object of this invention is to improve saw sharpeners by fabricating an inexpensive yet satisfactorily operative apparatus, which employs a new movement in so far as saw sharpeners are concerned, namely the reciprocating element together with the bracket and dog assembly' for operating the carriage.

Ancillary, objects and features will become apparent'in following the illustrated form of the invention.

In the drawings:

Figure 1 is a plan view of the device;

Figure 2 is a front view of the device shown in Figure l;

Figure 3 is a rear view of the device shown in Figure 1;

Figure 4 is an elevational side view of the device shown in Figure 1;

Figure 5 is a sectional view-taken approximately on the line 55 of Figure 1 and in the direction of the arrows;

Figure 6 is a view taken substantially on the 1ine'6-6 of Figure 5 and in the direction of the arrows, portions being broken away to'illustrate detail of construction;

Figure 7 is a view of the base'showing center.

lines schematically, the center lines being of the saw and plane passed through the. grinding wheel;. t

Figure 8 is a sectional view taken substantially on the line 8-8 of Figure 5 and in the direction of the arrows, and; l t

Figure 9 is a-perspective view of a bracket and dog which constitutes an important part of the invention, J j

2 Claims; (Cl. 764=1) In the instant invention, a base it is employed having indicia l2: struck on an are on a strip which is secured tothe base. This base forms a holder for the operative elements of the device. Disposed adjacent the indicia I2 is a slot [4 which accommodates a screw It having a nut l8 thereon. This screw passes through a bottom plate 23 which constitutes a part of the housing generally indicated at 22 and the nut rests on a washer which seats on the plate 28. By tightening the nut IS, the housing 22 may be locked in selected positions, which positions are indicated by the indicia 12.

The front end of the housing 22 and specifically, the front end of the plate 29 has a spacer strip 26 disposed thereon to elevate the front of the housing an amount equal to the elevation caused by the strip [3.

A motor 28 is disposed on the reciprocating plate or element 30 which has a pair of guide rods 32 and 34 respectively extending from the lower surface thereof. The guide rods pass through passages 36 and 38 Which are formed in the ends of the housing 22-. A connecting bar All is secured to the lower ends of the guide rods 32 and 34 adapted to abut the steps 44 and 46 formed by the upper end of the notches 48 and 50 in the ends of the housing. From inspection of Figure 5 the disposition of the connecting bar 40 is manifest that is, it extends through the housing longitudinally thereof and projects through the notches 48 and Eli.

Since the motor 28 is disposed on the element 5%], the motor reciprocates therewith. A cam follower 52 is fixed to the undersurface of the element 30 and engages the cam 54 which is fixed to the shaft 56. a

The motor 28 (see Figure 4) has a double sheave or pulley 58 secured to the shaft thereof. One of the pulleys has a belt Bil entrained therearourrd, which is also entrained around the pulley $2. This pulley is fixed to the shaft 64 which passes entirely'thrcugh the housing 22 and has a gear 65 fixed thereto. This gear is the smaller of two and is accordingly a pinion since it is meshed with a larger gear 68. The larger gear 68 is secured to the shaft 56 to obtain the proper drive connection.

As the motor 28 operates, the pulley 62 is also operated thereby causing the gear train'to be actuated for the purpose of operating the cam 54 which reciprocates the element 30.

Since the motor 28 reciprocates'with the element 30, an adjustable belt tightener is supplied; This belt ti htener consists of an arm. Iii

which is pivoted as at 72 to one side of the housing and which has an idler pulley 14 carried thereby. The belt 69 is entrained around the idler pulley. A spring I9 opposing the pivotal operation of the arm I9 and constantly pressing it in a direction so as to cause the idler I4 to tighten the belt, is attached to the housing and to the arm I9.

A support generally indicated at I8 is secured to the housing 22 and to the base by means of the pair of legs 82 and leg 89. A connecting member 8 3 is secured to the outer ends of each leg of the pair 82 and also to the leg Bil. The

screw 88 and rivets are employed for this purpose. The screw '86 being passed through the member 84 and the leg 89, forms a vertical pivot for the housing 22 on the base I9.

One of the other purposes of the support is to carry the bracket seenin Figure 9 for pivotal movement. An aperture in the bracket 99 accommodates the pivot pin 92 which is secured to a block 94 for pivotal movement. A spacer (Figure 5) 9B is secured to a pivot pin 93 which is carried by the bracket 92. The pivot pin 98 mounts the dog 99 which is adapted to engage in the teeth I of the rack I02.

The shape of the bracket 90 is of importance. There is a flat plate portion I04 with an ofiset I95 rising from one surface thereof. This offset is substantially L-shaped with the aperture 83 being at the junction of the legs. At the lower end of one of the legs, there is a suitable hole provided for accommodation of the pivot pin 98. A set screw I08 with a locking nut III) thereon is carried by the flat plate portion I94 and is adapted to engage the upper surface of the element 39 or more specifically, an extension H2 thereof (Figure 5). I In operation of this portion of the structure, when the element 39 is reciprocated, it strikes the set screw I08 which is used to define the limit of travel of the bracket. By so striking the set screw I98, the bracket 90 is pivoted about the pin 92 as an axis until striking the stop screw I09. This movement is reflected in the displacement of the pivot pin 93 in an arcuate path. Since'the center of pivotal movement of the dog 99 is bodily displaced in the arcuat path, the dog being in mesh in the teeth I93 causes the rack I02 to be moved. Each time the element 30 reciprocates, this operation takes place on the lifting part of the cycle thereof. During the lowering part of the cycle, the dog 99 slips to another tooth of'the rack iil2.

It is necessary that the teeth of the saw H 5, which exemplifies a typical workpiece, be sharpened or in some way treatedduring this cycle of operation of the element 30. Accordingly, a cutter, as the grinder H6, is mounted on an axle IIB which is disposed in the arm I20. I2!) is carried by the supporting member or bracket I22 which is in turn fixed to the reciprocating element 39. A pivot pin I24 is employed for holding the arm I29 on the support member I22. A slot I26 is provided in the arm I23 and a curved slot I28 is formed in the element I22. A screw I30 is passed through both of the slots which are intersecting, whereby pivotal adjustment of the arm I29 may be obtained by simply loosening the screw I30 and tightening it after the arm I29 has been moved to the desired position. This raises or lowers the grinder I I6 which is protected by the guard I 32 carried by the supporting element I22.

Accordingly, when the element 39 is recipro-v The arm cated, the cutter is also reciprocated so that its edge is in working or operative condition as shown at I36 in Figure 7, that is always over the center line of the saw.

In order to operate the grinder, a belt I40 is entrained around the pulley I42 which is fixed to the axle I8, and also around a part of the double sheave 5B. The motor 28 causes actuation of the grinder I It in this manner.

Means for supporting a carriage holding the saw H4 is provided. This means consists of a rail I44 having dovetail connection I46 with a runner I48. This runner forms a part of a carriage for supporting the saw II4. A clamp is arranged with the runner I48 for holding the saw H4 in selected vertically adjustable positions. This clamp includes a number of pairs of vertically rising or upstanding arms I52 having front and back plates I54 and I56 respectively carried at the upper ends thereof. Bolts I60 pass through the slots I62 formed in the pairs of arms I52 and have nuts thereon for pulling each arm of the pairs together to clamp the clamp plates I54 and I56 against the saw H4. The screws I69 act as the lower limit for the saw or the base therefor.

The rack I92 is fixed to the plate I so as to cause sliding operation of the runner I48 on the rail I44 in the manner previously described.

Having described the invention, what is claimed as new is:

1. A saw sharpener comprising a base, a housing pivoted to said base, a plate disposed on said housing, and means for guiding said plate in a reciprocatory travel, a motor, means secured to said plate and operatively connected with said motor for reciprocating said plate when said motor is operative, a saw clamp, a rail secured to said base, a carriage disposed on said rail carrying said clamp, a support disposed on said base, a bracket pivoted to said support and a dog carried by said bracket, a member having teeth secured to said carriage with said dog disposed in meshing relationship with the teeth, said bracket being disposed over said plate, an adjusting contact member operatively connected with said bracket and said plate to transfer preselected amounts of reciprocatory movement of said plate to pivotal movement of said dog whereby the amount of movement of the carriage is regulated, a cutter carried adjustably by said plate to engage the teeth of the saw during a part of each reciprocatory cycle of said plate.

2. A saw sharpener comprising a base, a housing pivoted to said base, a plate disposed on said housing, and .means for guiding said plate in a reciprocatory travel, a motor, meanssecured to said plate and operatively connected with said motor for reciprocating said plate when said motor is operative, a saw clamp, a rail secured to said base, a carriage disposed on said rail carrying said clamp, a support disposed on said base, a bracket pivoted to said support and a dog carried by said bracket, a member having teeth secured to said carriage with saiddog disposed in. meshing relationship with. the teeth, said bracket being disposed over said plate, an adjusting contact member operatively connected plate to engage the teeth of the saw during a part 7.5.

of each reciprocatory cycle of said plate, and

5 means drivingly connecting said motor and said Number cutter. 472,865

EDWARD J. DUQUE'I'I'E. 519,893 1,846,331

REFERENCES CITED I The following references are of record in the N b file of this patent: 12 5 UNITED STATES PATENTS Number Name Date I n 180,115 Covel July 25, 1876 Name Date Drake Apr. 12, 1892 Newton May 15, 1894 Hickey Feb. 23, 1932 FOREIGN PATENTS Country Date Switzerland July 15, 1935 

